A gas turbine engine may be used to power aircraft or various other types of vehicles and systems. The engine typically includes a compressor that receives and compresses an incoming gas such as air; a combustion chamber in which the compressed gas is mixed with fuel and burned to produce exhaust gas; and one or more turbines that extract energy from the high-pressure, high-velocity exhaust gas exiting the combustion chamber.
Recently, additive manufacturing (AM) methods have emerged, including for example the use of direct metal laser sintering/fusion (DMLS)/(DMLF), selective laser sintering (SLS), and electron beam melting (EBM), to eliminate the need for tooling, which is expected to result in significant cost and cycle time reduction in the manufacture of gas turbine engines. EBM uses an electron beam and DMLF uses a laser to solidify a metal powder. Parts are built in small layers (a few mils) in additive steps to produce a completed part. Fine powdered alloys are sintered and melted into a final part. The mechanics of the DMLF and EBM build processes are very similar, except for the fact that the DMLF process uses a laser and the EBM process utilizes an electron beam. Both energy sources melt fine layers of powder and fuse that layer to the subsequent layer below directly below it.
Additive processes such as DMLS, SLS, and EBM offer the ability to manufacture complex geometries on a small scale from CAD-based models. These processes have the ability to create components made of various aerospace alloys, including titanium, cobalt, nickel-based superalloys. In addition to manufacturing aerospace components as noted above, this ability can also be utilized to repair parts with complex geometries where no other conventional process is successful. Static components such as turbine nozzles and vane segments, as well as heat exchangers and fuel control manifolds, all have complex geometries that can benefit from such a repair process.
In many cases, however, it is not possible to fit the entire component (which may have been originally cast or fabricated through non-AM means) into the working range of the AM equipment. Also, considering that certain materials made with AM require special post-processing operations such as hot isostatic pressing (HIP) and coating, it may not be possible or desired to subject the entire component to these operations during repair.
Accordingly, it is desirable to provide improved methods for repairing components for use in gas turbine engines. Further, it is desirable to provide methods that allow gas turbine engine components, regardless of size or post-processing operations, to be repaired using additive manufacturing techniques. Furthermore, other desirable features and characteristics of the invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention.